The present invention relates to novel monoalkyl quaternary fatty ammonium derivatives of natural and synthetic oils, fatty acids and/or triglycerides and to their use in personal care products.
U.S. Pat. No. 4,012,398 describes quaternary halides of mink oil amides. These compounds, generally referred to as xe2x80x9cquatsxe2x80x9d, are disclosed as being useful emollients having surprisingly good hair conditioning properties. These quats are prepared, for example, by reacting either ethylene chlorohydrin or ethylene bromohydrin in a mixture of water and propylene glycol with an amide obtained by reacting, under anhydrous conditions, mink oil with certain amines using an alkaline catalyst such as sodium hydroxide.
While the mink oil derived quats described in the ""398 patent may be suitable for use in certain hair conditioning products, they are unlikely candidates for use in conditioning shampoos. Quats of compounds like mink oil such as those described in the ""398 patent while superior in some properties tend to have limited compatibility with anionic surfactants. Thus, while they may be suitable as conditioning agents, their use in shampoo could be problematic. Moreover, even if, sufficiently water soluble and compatible with anionic surfactants, mink oil quats do not provide suitable properties such as sufficient viscosity enhancement to warrant their inclusion in shampoo formulations.
Monoalkyl quats of other fatty acids are also known. For example, U.S. Pat. No. 4,978,526 discloses an amidoamine containing monoalkyl quat of 7 to 24 carbon atoms having a 2, 3 dihydroxypropyl ammonium group. U.S. Pat. No. 4,631,187 describes the use of a monofatty erucyl quat to make hair conditioners. Specifically, the quat described was dimethyl benzyl erucyl ammonium chloride. This compound did not include the use of an amidoamine.
Finally, hydroxyethyl behenamidopropyl dimonium chloride has been sold under the name INCROQUAT BEHENYL HE by Croda, Inc., 7 Century Drive, Parsippany, N.J. 07054.
The difficulty with most, if not all, of these compounds is that, at the activities desirable for commercial sale i.e. 25% to 90%, the resulting materials are solid or semi-solid at room temperature. This requires that both the additive and the shampoo, conditioner or other personal care product to which it will be added be heated during formulation. Heating these products is very expensive. In addition, it could have undesirable effects on the composition by promoting cross reactions between the other constituents, loss of color or clarity, precipitation and the like. In addition, in personal care products containing biological materials such as, for example, proteins, botanical extracts or vitamins, it can either volatize same or inactivate same. Therefore there remains a need for a commercially viable conditioning agent useful in shampoo and conditioners and the like, preferably one which is liquid at room temperature, at commercially desirable activities, and which can nonetheless promote viscosity without sacrifice of anionic surfactant compatibility.
The present invention relates to the monoalkyl quats of fatty acid materials having at least about 30% of at least a C-20 fatty acid component by weight. If 100% erucic acid is used, then 100% of the fatty acid constituents of the quats is C-22. If HEAR oil is used, then at least 30% of the fatty acids, and therefore at least 30% of the quats, will have a C-20 or higher chain length component. As should be clear, this means that the fatty acid component can be made up of one or more C-20 or greater fatty acids totally at least 30% by weight. In addition, the fatty acids, fatty acid containing oils, triglycerides, waxes and the like useful in accordance with the present invention contain fatty acids having an iodine value of greater than 0. In the case of fatty acid containing oils, this does not mean that all of the constituents must be unsaturated. However, overall, the iodine value must be greater than 0. Preferably, fatty acid constituents will be such that when reacted to form the monoalkyl quats of the present invention, and provided in solvents at activities as discussed herein, they will be liquid at room temperature. Thus, at least 30% of the fatty acid constituents of the resulting quats will generally range from about C-20 to about C-24 in carbon chain length. Finally, the monoalkyl quats of the present invention have superior viscosity properties when compared to quats made from, for example, mink oil, while at the same time, maintaining significant anionic surfactant compatibility allowing them to be easily formulated in, for example, shampoos.